Clothing made from cellulosic fabrics such as cotton and in particular indigo dyed denim fabrics have been common items of clothing for many years. Such clothing items are typically sold after they are sewn from sized and cut cloth. Such clothes and particularly denim clothing items are stiff in texture due to the presence of sizing compositions used to ease manufacturing, handling and assembling of the clothing items and typically have a fresh dark dyed appearance. After a period of wear, the clothing items, particularly denim, can develop in the clothing panels and on seams, localized areas of variations, in the form of a lightening, in the depth or density of color. In addition a general fading of the clothes can often appear in conjunction with the production of a "fuzzy" surface, some pucker in seams and some wrinkling in the fabric panels. Additionally, after laundering, sizing is substantially removed from the fabric resulting in a softer feel. In recent years such a distressed or "used and abused" look has become very desirable, particularly in denim clothing, to a substantial proportion of the public. To some extent, a limited pre-worn appearance, which has a uniform color density different than the variable color density in the typical stone-washed item, can be produced through prewashing or preshrinking processes.
The preferred methods for producing the distressed "used and abused" look involve stone washing of a clothing item. Stone washing comprises contacting a denim clothing item or items in large tub equipment with pumice stones having a particle size of about 1 to 10 inches and with smaller pumice particles generated by the abrasive nature of the process. Typically the clothing item is tumbled with the pumice while wet for a sufficient period such that the pumice abrades the fabric to produce in the fabric panels, localized abraded areas of lighter color and similar lightened areas in the seams. Additionally the pumice softens the fabric and produces a fuzzy surface similar to that produced by the extended wear of the fabric.
The 1 to 10 inch pumice stones and particulate pumice abrasion by-products can cause significant processing and equipment problems. Particulate pumice must manually be removed from processed clothing items (de-rocking) because they tend to accumulate in pockets, on interior surfaces, in creases and in folds. In the stone washing machine, the stones can cause overload damage to electric motors, mechanical damage to transport mechanisms and washing drums and can significantly increase the requirements for machine maintenance. The pumice stones and particulate material can clog machine drainage passages and can clog drains and sewer lines at the machine site. Further, the abraded pumice can clog municipal sewer lines, can damage sewage processing equipment, and can significantly increase maintenance required in municipal sewage treatment plants. These problems can add significantly to the cost of doing business and to the purchase price of the goods.
In view of the problems of pumice in stone washing, increasing attention has been directed to finding a replacement for stone washing in garment manufacture (see the Wall Street Journal, May 27, 1987, p. 1.). One avenue of investigation involves using a replacement stone such as a synthetic abrasive. In particular, ceramic balls such as those used in ball mills and irregular hard rubber pieces, which can be used without producing abraded by-products, have been experimented with in stone washing processes. These materials reduce the unwanted effects caused by particulate by-product pumice but do not significantly reduce machine damage caused by stones or the required maintenance on stone-containing laundry tubs. As a result, significant attention has been directed to producing a stone-free or pumice-free "stone washed" process that can produce a stone-washed denim look.
One disadvantage in pumice processing is that pumice cannot be used in tunnel washers, the largest commercial washing machines. Pumice cannot be circulated through the tunnel machines due to machine internal geometry. The use of larger-scale tunnel washers could significantly increase the productivity of the processes with the use of a stone or pumice-free composition that produces a genuine "stone-washed" look.
Barbesgarrd et al, U.S. Pat. No. 4,435,307 teach a specific cellulase enzyme that can be obtained from Humicola insolens which can be used in soil removing detergent compositions. Martin et al, European Pat. Application No. 177,165 teach fabric washing compositions containing a surfactant, builders, and bleaches in combination with a cellulase composition and a clay, particularly a smectite clay. Murata et al, U.K. Pat. Application No. 2,095,275 teach enzyme containing detergent compositions comprising an alkali cellulase and typical detergent compositions in a fully formulated laundry preparation. Tai, U.S. Pat. No. 4,479,881 teaches an improved laundry detergent containing a cellulase enzyme in combination with a tertiary amine in a laundry preparation. Murata et al, U.S. Pat. No. 4,443,355 teach laundry compositions containing a cellulase from a cellulosmonas bacteria. Parslow et al, U.S. Pat. No. 4,661,289 teaches fabric washing and softening compositions containing a cationic softening agent and a fungal cellulase in conjunction with other typical laundry ingredients. Suzuki, U.K. Pat. Application No. 2,094,826 teaches detergent laundry compositions containing a cellulase enzyme.
Dyed cellulosic clothing (such as denim) have been treated with desizing enzymes, detergents, bleaches, sours and softeners in prewashing and preshrinking processes. These variations are not intended to and do not duplicate the "stone-washed" look. A stone or pumice-free "stone-washed" process that produces the true stone-washed look has yet to be developed.